1. Field of the Invention
The invention relates to a method of and apparatus for controlling a crimping process which serves for connecting a contact with a conductor and in which a crimping tool of a crimping press is driven from a start position into a crimping position and subsequently into an end position.
2. Discussion of the Prior Art
Contacts are fixed to conductors, which have been previously stripped of insulation, by means of a crimping press, wherein at the same time a crush or press connectionxe2x80x94also called crimp connectionxe2x80x94is produced between the contact and the conductor insulation and a crush or press connection is produced between the contact and the electrically conductive conductor wire. The crimping press essentially consists of a stand, at which a drive for a crimping tool is arranged, and a crimping bar, which is guided and driven at the stand and which actuates the exchangeable tool for production of the crimp connection. The linear movement, which is necessary for the crimping process, of the tool is derived from, for example, a rotational movement which is generated by means of a motor, a transmission and a shaft, which is driven by the transmission, with an eccentric pin. Also known are crimping presses in which the linear movement is generated directly by means of hydraulic and/or pneumatic linear drives.
The sizes and shape of the contacts can vary widely according to the respective use, which makes different tools necessary. Also, the crimp zones of the contacts are differently formed. In the case of processing of a contact with an open crimp zone, the stripped conductor is brought about 5 to 10 millimeters over the contact and exactly positioned in the axial direction relative to the contact by means of a sensor. Upon lowering of the tool with the two crimping diesxe2x80x94a first crimping die for the insulation crimp and second crimping die for the wire crimpxe2x80x94the conductor is held by means of a mechanical device and lowered, in company, by the tool movement, wherein a crimp connection is produced between the contact and the conductor insulation and a crimp connection is produced between the contact and the electrically conductive conductor wire. The processing of a contact with a closed crimp zone is more costly, because the stripped conductor has to be guided into a tubular opening of the crimp zone. The tube of the contact is aligned, by appropriate centering, during an intermediate stop of the tool, which facilitates the pushing of the conductor wire into the tube. The processing of contacts with a closed crimp zone is more time-intensive by comparison with the processing of contacts with an open crimp zone.
The crimp connection arises between the movable first or second crimping die for the insulation crimp or for the wire crimp and a correspondingly constructed, fixedly arranged anvil. During the crimping process, the tool together with the dies is driven towards the anvil through a specific dimension. Moreover, the contact is similarly advanced through a contact indexing by means of the die movement by way of a mechanical system.
Crimping presses with a tool stroke of 30 millimeters or 40 millimeters are the general standard in conductor processing. The crimping presses predominantly operate on the eccentric principle, wherein the linear movement of the die is produced by means of the eccentric pin arranged on the driven shaft. The rotating eccentric pin stands in loose connection with the crimping bar and moves the crimping bar linearly. The rotational movement can also be converted into the linear movement by means of a connecting rod. Eccentric crimping presses work rapidly and are economic in manufacture.
However, the fixed stroke preset by the eccentric pin is disadvantageous in these crimping presses. For tools with different stroke lengths, a mechanical action has to be undertaken at the crimping press, in that the dead centers of the eccentric pin are displaced or the shaft with the eccentric pin is exchanged. A subsequent adjustment is necessary in each case.
Accordingly, it is an object of the present invention to provide a crimping press, in which the tool stroke is settable, for the production of crimp connections while avoiding the disadvantages of the known equipment.
Pursuant to this object, and others which will become apparent hereafter, one aspect of the present invention resides in a method for controlling a crimping process for connecting a contact with a conductor, which method comprises the steps of driving a crimping tool of a crimping press from a start position into a crimping position and subsequently into an end position, and selecting the start and end positions of the crimping tool for processing different contacts.
In another embodiment of the inventive method the crimping tool is moved between the start position and the end position by a rotational movement in which the start and end are at different locations.
In still another embodiment of the inventive method the crimping tool, in a succeeding crimping process, is moved in a direction of rotation that is opposite to a direction of rotation of a preceding crimping process.
In still a further embodiment of the inventive method the respective position of the crimping tool is detected and used for controlling the crimping. Furthermore, the method includes selecting any single one of a crimping process for checking the crimping connection, a crimping process with an intermediate stop for positioning the conductor, and a crimping process with a preselected stroke.
Another aspect of the invention resides in an apparatus for producing a crimping connection, which apparatus includes a motor-driven crimping tool and means for selectively controlling position and movement of the crimping tool.
In another embodiment of the apparatus the crimping tool includes a drive motor while the control means includes a computer operatively connected to the drive motor so as to control the drive motor according to selectable prescribing data and in dependence on a respective position of the crimping tool.
In still another embodiment of the inventive apparatus the control means includes a transmitter operatively arranged to detect the respective position of the crimping tool. The control means can further include an inverter operatively connected between the computer and the drive motor so as to control the drive motor in accordance with the specification data from the computer.
In yet a further embodiment of the crimping apparatus pursuant to the invention, an operator terminal is provided which is in operative communication with the control means. The operator terminal includes a keyboard or keypad and a display for input and visualization of user and system data. Furthermore, a rotary knob is provided at the operator terminal for selecting the start and end position of the crimping tool.
The advantages achieved by the invention are essentially to be seen in that in the processing of different contacts no re-equipping of the crimping press is necessary and that also small contacts are able to be processed. It is further of advantage that no sensors for monitoring the start position or intermediate position of the tool with the dies are needed. With the crimping press according to the invention the number of crimping processes per unit time can be substantially increased without change in the mechanical system. Moreover, the control of the crimping press recognizes the exact tool position at any time, whereby a simple evaluation of the crimping forces is made possible and other machines participating in the crimping process can be synchronized.
The various features of novelty which characterise the invention are pointed out with particularity in the claims annexed to and forming a part of the disclosure. For a better understanding of the invention, its operating advantages, and specific objects attained by its use, reference should be had to the drawing and descriptive matter in which there are illustrated and described preferred embodiments of the invention.